Existing microwave antennas include a wide variety of configurations for various applications, such as satellite reception, remote broadcasting, or military communication. The desirable characteristics of low cost, light-weight, low profile and mass producibility are provided in general by printed circuit antennas wherein flat conductive elements are spaced from a single essentially continuous ground element by a dielectric sheet of uniform thickness. The antennas are designed in an array and may be used for communication systems such as identification of friend/foe (IFF) systems, personal communication service (PCS) systems, satellite communication systems, and aerospace systems, which require such characteristics as low cost, light weight, low profile, and a low sidelobe.
The bandwidth and directivity capabilities of such antennas, however, can be limiting for certain applications such as space applications. Furthermore, while a microstrip patch antenna is advantageous in applications requiring a conformal configuration, e.g. in aerospace systems, mounting the antenna presents challenges with respect to the manner in which it is fed such that conformality and satisfactory radiation coverage and directivity are maintained and losses to surrounding surfaces are reduced. More specifically, increasing the bandwith of a phased array antenna with a wide scan angle is conventionally achieved by dividing the frequency range into multiple bands. This approach results in a considerable increase in the size and weight of the antenna while creating a Radio Frequency (RF) interface problem. Also, gimbals have been used to mechanically obtain the required scan angle. Again, this approach increases the size and weight of the antenna, and results in a slower response time.
Thus, there is a need for a lightweight patch dipole phased array antenna with a wide frequency bandwith and a wide scan angle, and that can be conformally mountable to a surface.